Contact arrangement in coordinate switches

ABSTRACT

Multiple bars, arranged in rows and columns, extend through different banks of a switch assembly and comprise fixed contacts to be engaged directly by adjacent movable contacts. The movable contacts extend from the faces of conductive flexible strips that are suspended between rows of the multiple bars. Operation of a first actuator flexes the contact strips of a selected column of a switch bank toward respective multiple bars, and operation of a second actuator moves the flexible strips of selected rows longitudinally such that detent prongs near respective selected contacts function as inclined planes to complete engagement of the selected contacts. Each selected contact is held closed as long as only the second actuator is operated.

United States Patent Warman [54] CONTACT ARRANGEMENT IN COORDINATE SWITCHES [72] Inventor: Bloomfield J. Warman, Milan, Italy [73] Assignee: GTE Automatic Electric Laboratories,

lnc., Northlake, Ill.

[22] Filed: July 16, 1970 [21] Appl. No.: 55,503

[52] U.S.Cl ..200/177,335/108,335/112, 335/1 13 [51] Int. Cl. ..H0lh 67/02 [58] Field olSearch ..200/175, 176,177,178; 335/108,1l1,112,113,116

[56] References Cited UNITED STATES PATENTS 3,205,319 9/1965 Anderson et a1 ..200/16 3,529,113 9/1970 Vazquez et a1. ..335/112 1 Feb. 29, 1972 OTHER PUBLICATIONS Branham, IBM Technical Disclosure Bull May 1968, Vol. 10,

[57] ABSTRACT Multiple bars, arranged in rows and columns, extend through different banks of a switch assembly and comprise fixed contacts to be engaged directly by adjacent movable contacts. The movable contacts extend from the faces of conductive flexible strips that are suspended between rows of the multiple bars. Operation of a first actuator flexes the contact strips of a selected column of a switch bank toward respective multiple bars, and operation of a second actuator moves the flexible strips of selected rows longitudinally such that detent prongs near respective selected contacts function as inclined planes to complete engagement of the selected contacts. Each selected contact is held closed as long as only the second actuator is operated.

5 Claims, 4 Drawing Figures PATENTEDFEBZSIHYE SHEET 1 BF 3 INVENTOR BLOOMFlELD J. WARMAN ATTORNEY ET IN ATED POSITION sum 2 BF 3 PATENTEUFEBZQ I972 .lll

PAIENTEUFEB29 m2 SHEET 3 [IF 3 RETURN SPRING ASSEMBLY we TN A R RRA m m H ITE M TET O mmm B W W O O 3 RETURN SPRING ASSEMBLY OPERATlNG MAGNET BACKGROUND OF THE INVENTION This invention pertains to coordinate, electromagnetical switches and particularly to switches that have latching means to retain contacts closed after the releasing of one of two coordinate actuators that had been operated simultaneously to close the contacts.

A type of switch commonly used in telephone switching offices of small size or medium size for connecting line circuits utilizes two pair of contacts connected in series for each connection, a pair of contacts for each connection being operated by a respective tens relay and unit relay. A switch of this type is described in [1.8. Pat. No. 2,573,889 issued to H. P. Boswau on Nov. 6, I951. The contacts of the tens relays of each switch bank are arranged in a rectangular coordinate array, and a desired row of the contacts is selected by operation of a units relay. A feature of this type of switch is the interconnection of all movable contacts in each of these rows as a result of their fabrication from a single strip of conductive spring material. The fixed contacts in these same rows differ from those of other types of coordinate switches in that they are multiple bars; that is, each pair of contacts has a spring contact operating directly against the face of a multiple bar. Guide holes through the base of each bank position the multiple bars adjacent respective movable, spring contacts, each of the multiple bars being inserted through corresponding guide holes of a plurality of adjacent switches. In a common arrangement, the contacts of all the units relays are connected to the same switching line, 44 line, and therefore only one connection at a time can be completed in any one bank.

SUMMARY OF THE INVENTION The switch of this invention is like that described in US. Pat. No. 2,573,889 cited above in that multiple bars function as fixed contacts, and movable contacts in a row are fabricated from a single strip of conductive spring material. In the type of switch described above, contact portions extend outwardly from one edge of each of the conductive strips, and only the extending portions are moved by operation of the tens relays while the interconnecting portions are stationary. In the present switch, the movable contacts are raised from the faces of the conductive strips, and the strips themselves are movably suspended between rows of multiple bars. The operation for closing contacts is like that of crossbar switches in that two actuators for different coordinates are operated simultaneously to close a selected set of contacts. Operation on one actuator flexes conductive strips along a selected column to move their contacts toward respective marking bars, and operation of another actuator moves selected strips longitudinally and causes them to flex still further until they engage respective marking bars. Latching means is provided so that one of the actuators, called a marking actuator, can be released for reuse while the other actuator, called a hold actuator, in cooperation with the latching means maintains a set of contacts closed as long as it is operated.

The arrangements for operating and holding cross-points operated make possible a plurality of line connections simultaneously through a single bank of switches that are interconnected by removable multiple bars. For example, a bank of the previous type of relay switch, described above, that has multiple bars for I lines in a 10x10 matrix has access to a single switching line or link; whereas, in a switch according to the present invention, I00 lines connected to the multiple bars may have access to 10 links connected to different ones of the contact strips.

The marking actuators are selectively operable to press perpendicularly the contact strips so they are flexed along a column of multiple bars which function as fixed contacts. The

strips that are subsequently moved longitudinally by operation of hold magnets are closed.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a diagrammatic, side view of a preferred embodiment of a switch bank according to this invention;

FIG. 2 is a fragmentary oblique view of a plurality of switch banks of FIG. I to show their interconnection by multiple bars;

FIG. 3 shows an enlarged portion of the switch banks of FIG. I; and

FIG. 4 is an oblique view of a portion of the switch bank.

A DESCRIPTION OF THE PREFERRED EMBODIMENT An arrangement of contact strips marking bars, multiple bars, and guide pillars of a switch bank according to this invention is shown in FIG. 1. In this illustration four contact strips designated T, R, P, and H are used for each line that is to be connected to the switch bank. The contact strips are fabricated from flexible, conductive spring material. The ends of each group of four contact strips at the left side of the drawing are shown connected to return springs 11 to urge the contact strips to their normal positions, and the opposite ends of each group of four contact strips are connected to hold actuators 12 for moving the contact strips a short distance to the right to an operate position when a respective actuator is operated. In a I0 l0 matrix, each contact strip has 10 evenly spaced spring contacts that have been pressed slantingly outwardly from the strip as represented by the contact 13 of the upper contact strip P, and each contact has an adjacent detent prong 14 also pressed from the strip. It will become apparent from the description of the operation of the switch bank that the end of the detent 14 extends farther than the end of the contact 13 from the surface of the contact strip T in order that the detent prong can engage a respective guide pillar. The contacts along any one of the contact strips form a row of interconnected contacts of a coordinate array, and the corresponding contacts on the different strips form columns of the array. The contacts extend alternately from both sides of each of the contact strips so that all contacts of any one column face in the opposite direction from those in an adjacent column.

An individual switch bank is not complete until it is multiplied with similar banks because multiple bars that are inserted through adjacently mounted similar switch banks function as fixed contacts opposite the spring contacts of the contact strips. The fragmentary view of FIG. 2 shows the location of multiple bars. For example, a multiple bar 15 extends perpendicularly through the base of a switch bank 18 between an insulated, triangular guide pillar l6 and twin spring contacts 17, through the base of a switch bank 20 adjacent corresponding twin spring contacts 19, through the base of a switch bank 22 adjacent the twin, spring contacts 21, and likewise through other switch banks that are connected in multiple. The spring contacts in the adjacent column face in the opposite direction and the multiple bars are inserted through holes 23 adjacent that side of a guide pillar 24 that also faces the opposite direction.

The locations and functions of multiple bars and guide pillars relative to the contact strips are shown clearly in FIG. 3. One row of multiple bars is along one side of each contact strip to function as fixed contacts for spring contacts facing in one direction, and another row of multiple bars extend along the other side of each contact strip to function as the fixed contacts for the spring contacts facing in the opposite direction. For example, the upwardly facing contacts of a contact strip T including contacts 25, 26, and 27 have a row of multiple bars or fixed contacts including the multiplex bars 28, 29, and 30, and downwardly facing contacts including contacts 31 and 32 of the same contact strip have a row of multiple bars including multiple bars 33 and 34.

Preferably, the guide pillar 24 of FIG. 2 has a triangular cross section, and it is integral molded part of the base of the switch bank. One side of each pillar is adjacent a side of a multiple bar, for example, one side of the pillar 16 is adjacent to one side of the multiple bar 15, and the corner of the pillar opposite the multiple bar is contingent and adjacent one of the contact strips. The corners contingent to the contact strips function to maintain the contact strips in a normally straight line and function during operation of a switch bank as a fulcrum cooperating with an operated marking bar to determine a point of deflection of the contact strips. In addition, a side of each pillar adjacent to the fulcrum functions as an inclined plane to be engaged by a respective detent prong as described below.

Each switch bank has a marking bar extending along each column of contacts, and the marking bars are individually operable longitudinally to deflect the contact strips of the switch bank. Since alternate contacts on each contact strip face opposite directions, alternate marking bars are operable in opposite directions. For example, a marking bar actuator 36 is mounted at the bottom of the switch bank of FIG. 1 to operate marking bar 35 that is associated with the first column of contacts downwardly; whereas the marking bar actuator 38 is mounted at the top of the switch bank to operate marking bar 37 that is associated with a second column of contacts upwardly. In any column where a respective marking bar is operated, spring contacts of the different groups of contact strips may be in any one of three different positions according to whether the hold actuators for the respective groups of contact strips are in (l) an unoperated position, (2) an operated position as a result of a previous selection, or (3) in an operated position as a result of the present selection.

In FIG. 1, a marking bar actuator 39 is shown operated, and its marking bar 40 is shown in an upward operated position. The hold actuators 41 and 42 of the lower two groups of four conductors are unoperated, and in response to the operation of the marking bar actuator 39, spring contacts corresponding to the spring contact 43 have been moved only part way toward their respective marking bars. The outer ends of the detent prongs corresponding to the detent prong 44, overlap but do not engage the adjacent sides of the guide pillar corresponding to the guide pillar 50. 1

The hold actuator 12 of the upper group of four conductors have been operated previously as a result of selection and operation of contacts in the seventh column, and the marking bar for the presently selected fourth column has no effect on these conductors for these conductors were positioned by the previous operation so that the finger projections of the marking bar 40 extend through holes of the upper group of contact strips as described below.

The contacts operated for the present selection are the contacts of the second group of contact strips from the top as a result of the operation of the hold actuator 45 immediately afier the operation of the marking actuator 39. As described above with reference to the lower two groups of conductors, operation of the marking bar 40 before operation of a hold actuator only partly closes the gap between the finger contacts and respective marking bars and positions the ends of the detent prongs opposite their guide pillars. After partial deflection of the contact strips by the operation of the marking bar 40, the hold actuator 45 operates to move the contact strips to the right to engage the detent prongs of the selected contacts with their respective guide pillars 48. As each detent prong engages the facing side of the respective triangular guide pillar, the inclined surface of the pillar deflects the respective contact strip still further to engage the contacts 46 with their respective multiple bar. After the hold actuator 45 has been operated, the marking bar actuator 39 is released and the detents 47 of the selected contact strips maintain the respective spring contacts in engagement with their multiple bars as long as the hold relay 45 is operated. When the connection is to be terminated, the hold actuator 45 is released, and a return spring 49 moves the contact strips T, R, I, and H of the second group from the top, to the left to disengage their detent prong from the guide pillars so that the portion of the contact strips in the fourth column return to a normal straight position.

In FIG. 4, the detent prong 47 is held against the side of the pillar 48 by operation of the hold magnetic 45 to close the cross-point comprising the twin contacts 46 and the multiple bar 51. During fabrication of the contact strip T, the detent prong 47 inclined toward its respective contacts 46, has been pressed out and turned up at an obtuse angle to form a smooth, rounding edge on one side of the hole formed by the process. After the marking bar actuator is operated, but before the hold actuator 45 is operated, the finger projection 52 presses upwardly on the contact strip T at a point slightly closer to the hold actuator 45 than the position of the rounding edge formed by the inner end of the detent prong 47. As the contact strip T is moved to the right toward its hold actuator, the marking bar finger projection 52 becomes aligned with the hole that has been formed by pressing out of the detent prong 47. The marking bar 40 is not then engaged with the selected contact strips, and it can be released to return unselected contact strips along the marking bar to their normal positions.

In each switch bank, one cross-points can be completed for each group of contact strips. The reoperation of the same marking bar 40 or the operation of any other marking bar of the switch bank while the actuator 45 is still operated does not disturb the position of the contact strips at a closed cross-point because the finger projections of the later operated marking bars merely extend through the holes at the inner ends of the detent prongs 47. The rounding edge at the inner end of the detent 47 prevents excessive friction between the insulated tip of the finger projection 52 and the contact strip T, should the hold relay 45 be released before the marking bar actuator 39 is released.

The base 53 is preferably molded from insulating material so that the grooves 54 and the guide pillars 48 can be readily formed as part of the base. The marking bars 40 may be fabricated from sheet metal, and the tips of the finger projections 52 may be covered with insulating material to prevent electrical contact between the marking bars and the contact strips. One edge of each of the marking bars 40 is straight and fits into one of the grooves that are properly spaced relative to the columns of guide pillars and spring contacts of mounted contact strips. The opposite edge of each of the marking bars has fingers 55 extending outward between the contact strips. The finger projections 52 of alternate marking bars 40 extend in opposite directions along their respective column to correspond to the direction in which the spring contacts 46 for the column have been raised from the contact strips.

Suitable, well-known types of actuators 39 and 45 can be mounted by usual means along the edges of the molded bases 53. The mounting arrangements of the marking bars 40 facilitate the replacement of any group of the contact strips T, R, P, and H. An end of each group of the contact strips is connected by a removable pin 56 to a respective hold actuator 45 or to a return spring 49. When the pins for a group of contact strips are removed, the group can be readily lifted from between the pillars 48 and the fingers 55 'of the marking bars 40.

lclaim: I

l. A coordinate cross-point switch comprising:

a plurality of fixed contacts arranged in rows and columns,

a flexible contact strip of conductive spring material disposed along each of said rows of fixed contacts, said contact strips being mounted parallel face to face and being selectively movable longitudinally in the direction of said rows between a normal position and an operate position, spring contact and latching means projecting from at least one face of each of said contact strips at its intersection with each of said columns, all of said spring contact and latching means in any one of said columns being positioned on the same side of the respective contact strips, and each of said spring contact and latching means located slightly to one side and in front of a respective one of said fixed contacts to form therewith a normally open pair of contacts. marking means operative to flex in any selected one of said columns, and in the directionthereof, all of said contact strips, except those already in a flexed position from a previous operation, toward respective ones of said fixed contacts of said selected column until each of said spring contact and latching means of the contact strips that are being flexed in the selected column overlap the side of a respective one of said fixed contacts, the operation of said marking means partly closing the gaps between said pairs of contacts that are not previously operated in said selected column, actuation means operative to move selected ones of said contact strips from said normal position to said operate position in a direction to complete the engagement of said spring contact and latching means of said selected column with respective ones of said fixed contacts, and

said marking means upon being released permitting said contact strips, except those with engaged contact and latching means in said selected column, to return to a normal unflexed position in said selected column while operation of said actuation means in cooperation with said spring contact and latching means maintains closed said pairs of contacts of said selected contact strip in said selected column.

2. A coordinate cross-point switch according to claim 1 in which said fixed contacts are parallel multiple bars extending across the width of said contact strips.

3. A coordinate cross-point switch according to claim 2 having an insulated guide pillar for each of said fixed contacts,

each guide pillar having a triangular cross section and having one side disposed along that side of a respective one of said marking bars facing away from said spring contacting and latching means, the corner opposite said one side functioning as a pivot for an adjacent one of said contact strips, said spring contacting and latching means for each of said cross-points including a prong for overlapping an adjacent side of a respective one of said guide pillars in response to operation of a respective one of said marking means, and said prong in response to operation of said actuator means engaging said adjacent side and functioning as an inclined plane to engage a respective fixed contact with said contact and latching means.

4. A coordinate cross-point switch according to claim 3 having a molded base including said guide pillars projecting therefrom and a groove molded therein along each of said columns, said marking means for each column comprising a marking bar with an edge slidably mounted in a respective one of said grooves and a plurality of fingers extending from the opposite edge thereof, said fingers being spaced according to said rows, each finger having a lateral projection to engage a respective one of said contact strips to flex it in response to selective operation of the respective marking bar.

5. A coordinate cross-point switch according to claim 4 in which each of said contact strips has a hole at each of its crosspoints adjacent each point that is connected by said lateral finger projections of said marking bars in response to their operation before operation of said actuation means, said holes being opposite respective ones of said lateral finger projections after operation of respective actuation means to prevent flexing of previously operated ones of said contact strips by operation of said marking bars.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 4 .303 Dated February 29 1972 I BLO OMFIELD J. WARMAN It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the cover page Line [73] delete INC and add INCORPORATED Column 5 line 25 delete "connected" and add contacted Signed and sealed this 17th day of April 1973 (SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attestlng Officer Commissioner of Patents ORM PO-1050 (10-69) USCOMM-DC 60376-P69 fr u.s. GOVERNMENT-PRINTING OFFICE: I969 0-366-334 UNITED STATES PATENT OFFICE CERTIFICATE F CGEC'HN Patent 3.646.303 Dated Fe ruary 1972 In BLOOMFIELD J. WARMAN It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the cover page Line [73] delete INC." and add INCORPORATED Column 5, line 25, delete "connected" and add contacted Signed and sealed this 17th day of April 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK- Attesting Officer Commissioner of Patents ORM PO-IOSO (10-69) USCOMM-DC 60376-1 69 U,S. GOVERNMENT PRINTING OFFICE: 1969 0-366-334 

1. A coordinate cross-point switch comprising: a plurality of fixed contacts arranged in rows and columns, a flexible contact strip of conductive spring material disposed along each of said rows of fixed contacts, said contact strips being mounted parallel face to face and being selectively movable longitudinally in the direction of said rows between a normal position and an operate position, spring contact and latching means projecting from at least one face of each of said contact strips at its intersection with each of said columns, all of said spring contact and latching means in any one of said columns being positioned on the same side of the respective contact strips, and each of said spring contact and latching means located slightly to one side and in front of a respective one of said fixed contacts to form therewith a normally open pair of contacts. marking means operative to flex in any selected one of said columns, and in the direction thereof, all of said contact strips, except those already in a flexed position from a previous operation, toward respective ones of said fixed contacts of said selected column until each of said spring contact and latching means of the contact strips that are being flexed in the selected column overlap the side of a respective one of said fixed contacts, the operation of said marking means partly closing the gaps between said pairs of contacts that are not previously operated in said selected column, actuation means operative to move selected ones of said contact strips from said normal position to said operate position in a direction to complete the engagement of said spring contact and latching means of said selected column with respective ones of said fixed contacts, and said marking means upon being released permitting said contact strips, except those with engaged contact and latching means in said selected column, to return to a normal unflexed position in said selected column while operation of said actuation means in cooperation with said spring contact and latching means maintains closed said pairs of contacts of said selected contact strip in said selected column.
 2. A coordinate cross-point switch according to claim 1 in which said fixed contacts are parallel multiple bars extending across the width of said contact strips.
 3. A coordinate cross-point switch according to claim 2 having an insulated guide pillar for each of said fixed contacts, each guide pillar having a triangular cross section and having one side disposed along that side of a respective one of said marking bars facing away from said spring contacting and latching means, the corner opposite said one side functioning as a pivot for An adjacent one of said contact strips, said spring contacting and latching means for each of said cross-points including a prong for overlapping an adjacent side of a respective one of said guide pillars in response to operation of a respective one of said marking means, and said prong in response to operation of said actuator means engaging said adjacent side and functioning as an inclined plane to engage a respective fixed contact with said contact and latching means.
 4. A coordinate cross-point switch according to claim 3 having a molded base including said guide pillars projecting therefrom and a groove molded therein along each of said columns, said marking means for each column comprising a marking bar with an edge slidably mounted in a respective one of said grooves and a plurality of fingers extending from the opposite edge thereof, said fingers being spaced according to said rows, each finger having a lateral projection to engage a respective one of said contact strips to flex it in response to selective operation of the respective marking bar.
 5. A coordinate cross-point switch according to claim 4 in which each of said contact strips has a hole at each of its cross-points adjacent each point that is connected by said lateral finger projections of said marking bars in response to their operation before operation of said actuation means, said holes being opposite respective ones of said lateral finger projections after operation of respective actuation means to prevent flexing of previously operated ones of said contact strips by operation of said marking bars. 